// Copyright 2014 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include "net/base/net_string_util.h"

#include "base/i18n/i18n_constants.h"
#include "base/i18n/icu_string_conversions.h"
#include "base/strings/string_util.h"
#include "third_party/icu/source/common/unicode/ucnv.h"

namespace net {

const char* const kCharsetLatin1 = base::kCodepageLatin1;

bool ConvertToUtf8(const std::string& text, const char* charset,
    std::string* output)
{
    output->clear();

    UErrorCode err = U_ZERO_ERROR;
    UConverter* converter(ucnv_open(charset, &err));
    if (U_FAILURE(err))
        return false;

    // A single byte in a legacy encoding can be expanded to 3 bytes in UTF-8.
    // A 'two-byte character' in a legacy encoding can be expanded to 4 bytes
    // in UTF-8. Therefore, the expansion ratio is 3 at most. Add one for a
    // trailing '\0'.
    size_t output_length = text.length() * 3 + 1;
    char* buf = base::WriteInto(output, output_length);
    output_length = ucnv_toAlgorithmic(UCNV_UTF8, converter, buf, output_length,
        text.data(), text.length(), &err);
    ucnv_close(converter);
    if (U_FAILURE(err)) {
        output->clear();
        return false;
    }

    output->resize(output_length);
    return true;
}

bool ConvertToUtf8AndNormalize(const std::string& text, const char* charset,
    std::string* output)
{
    return base::ConvertToUtf8AndNormalize(text, charset, output);
}

bool ConvertToUTF16(const std::string& text, const char* charset,
    base::string16* output)
{
    return base::CodepageToUTF16(text, charset,
        base::OnStringConversionError::FAIL, output);
}

bool ConvertToUTF16WithSubstitutions(const std::string& text,
    const char* charset,
    base::string16* output)
{
    return base::CodepageToUTF16(text, charset,
        base::OnStringConversionError::SUBSTITUTE,
        output);
}

} // namespace net
